Types of Hearing Loss

Most hearing loss falls into one of two categories conductive or sensori-neural. Conductive hearing loss occurs when the sound waves cannot be conducted from the outer or middle ear into the inner ear. A blockage in the ear canal, a punctured eardrum, a middle-ear infection or any problem that would prevent the eardrum or ossicles from vibrating produces a conductive loss.   

Sensori-neural hearing loss occurs either in the inner ear (the sensory part) or in the auditory nerve (the neural part). When sound reaches the inner ear but is not correctly perceived, or is correctly perceived but cannot reach the brain, the resulting loss is considered sensori-neural. Damage to the hairs or nerve cells in the cochlea or damage to the auditory nerve produces a sensori-neural loss. There are several factors that can clue you in. If your own voice sounds loud to you and other voices sound muffled, chances are your loss is conductive. Ringing in the ears, hearing better in noisy surroundings than in quiet surroundings, tolerating noises other people feel are too loud and speaking too softly for other people to hear are also characteristic of conductive loss.   

If your voice sounds soft to you and you have difficulty understanding speech, you may have a sensori-neural loss which is also known as nerve deafness. If you are sensitive to loud sounds, have difficulty hearing speech in noisy places and tend to speak in a loud voice, you probably have a sensori-neural problem. Ringing or buzzing in the ears, a condition known as tinnitus, can also occur, but since this symptom is characteristic of both types of hearing loss, your best bet is to have your ears examined by a doctor.   

Can you have both types? Yes. This is what is known as mixed hearing loss. It occurs when there are problems in both conduction and interpretation of sound. A loud explosion, for example, could puncture the eardrum and damage the hair cells in the cochlea, causing both conductive and sensori-neural loss. Sensori-neural loss is more common than conductive loss, primarily because aging-related hearing loss is sensori-neural. Experts estimate that about 90 percent of all hearing loss is sensori-neural.   

Both types can be profound and can lead to deafness, but sensori-neural loss is usually irreversible. Conductive loss, on the other hand, can often be reversed.